Conventionally, a baby wipe consists of a small sheet of fibrous material impregnated with an aqueous cleansing preparation. Such wipes have been found to be very acceptable as a means of cleansing urine and bowel motions from a baby's skin, for example in the course of changing the baby's diaper. However, although effective for the purpose of cleansing, such wipes do not, normally, of themselves, provide any protection for the skin against the effects of subsequent wetting or soiling, and it is therefore common practice, after using the baby wipe, to apply an oil-based material, for example in the form of a cream.
EP-A-328355 and EP-A-0613675 describe an oil-in-water emulsion for use, inter alia, in baby wipes. It is noted, however, that no reference is made in either to the size of the oil particles in the emulsion, a matter which is discussed below as being of considerable significance. However, in the case of EP-A-328355, it is specifically stated that polymeric emulsification is used.
It is an object of the present invention to provide, inter alia, a baby wipe, and a liquid preparation for use therein which both has an effective cleansing action and which contains an oil to afford protection to the skin. The liquid preparation is to be stable, so as to permit storage thereof and, more importantly, the storage of baby wipes impregnated therewith, for extended periods without deterioration. The liquid preparation should also be such that, despite the presence of the oil, it does not give rise to an unacceptably sticky feel on the skin, bearing in mind that some of the material will inevitably end up on the skin of the person handling the baby, rather than on the baby's own skin.
As in the case of the product described in EP-A-328355 and EP-A-0623675 mentioned above, the approach adopted in the present invention is to use an oil-in-water emulsion, in which there is a high proportion of water to provide the cleansing action, and in which the droplets of oil provide the desired skin protection. However, one of the major problems encountered in employing this approach is that of making the emulsion sufficiently stable.
Some known cosmetic and toiletry products which use such emulsions achieve stability of the emulsion by adding materials to the aqueous phase to give it a high viscosity. However, that option is not desirable where baby wipes are concerned, since the increased viscosity of the aqueous phase would both impair the cleansing action and make it difficult to apply the liquid to the fibrous sheets. Polymeric emulsification, as described in EP-A-328355, is also disadvantageous because of the increase in viscosity which it produces.